Editing Freckled duck

{{short description|Species of bird}}
{{Use dmy dates|date=September 2020}}
{{use Australian English|date=May 2011}}
{{speciesbox
| name = Freckled duck
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=BirdLife International |date=2016 |title=''Stictonetta naevosa'' |volume=2016 |page=e.T22679836A92831716 |doi=10.2305/IUCN.UK.2016-3.RLTS.T22679836A92831716.en |access-date=19 November 2021}}</ref>
| image = Freckled-Duck-male.jpg
| image_caption = Male
| image2 = Freckled-duck-female.jpg
| image2_caption = Female
| grandparent_authority = [[Hans von Boetticher|Boetticher]], 1950
| genus = Stictonetta
| parent_authority = [[Ludwig Reichenbach|Reichenbach]], 1853
| display_parents = 3
| species = naevosa
| authority = ([[John Gould|Gould]], 1841)
}}

The '''freckled duck''' ('''''Stictonetta naevosa''')'' is a waterfowl species endemic to Australia. The freckled duck has also been referred to as the '''monkey duck''' or '''oatmeal duck'''.<ref name=:21>{{cite book|last=Johnsgard|first=P. A.|year=2010|chapter=Tribe Stictonettini (Freckled Duck)|title=Ducks, Geese, and Swans of the World|pages=97–100|chapter-url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1006&context=biosciducksgeeseswans}}</ref> These birds are usually present in mainland Australia, but disperse to coastal and subcostal [[wetland]]s in the dry period. During such times it is common for the freckled duck population to congregate in flocks in the same area, giving the impression that they are more common than they really are.<ref name=:16>{{cite report|last=Garnett|first=S.|year=1992|title=The Action Plan for Australian Birds|location=Canberra|publisher=Australian National Parks and Wildlife Service}}</ref>

The freckled duck population is at risk of further reduction from [[habitat destruction]], droughts and game hunting. Often habitat destruction and drought can lead to an increase in hunting, as the freckled duck is forced to disperse into more coastal ranges where they may not be recognised as a protected species.<ref name=:23>{{cite journal|last=Loyn|first=R. H.|year=1991|title=Assessing and managing the impact of duck hunting in Victoria - a new approach|journal=Wildfowl|volume=42|pages=155–161}}</ref>

In the past few decades, several institutions have established breeding programs to aid in supplementation of the freckled duck population. Such establishments included, but are not restricted to the [[Hunter Estuary Wetlands|Hunter Wetlands Centre Australia]],<ref>{{cite web |title=Frecked Ducks in Residence |url=https://wetlands.org.au/living_wetlands/freckled-ducks-in-residence/ |website=Hunter Wetlands Centre Australia |access-date=13 May 2023}}</ref> [[Slimbridge Wetland Reserve|Slimbridge Wetlands]], [[Melbourne Zoo]], [[Bronx Zoo]], [[Adelaide Zoo]], [[Healesville Sanctuary]], and [[Tidbinbilla Nature Reserve]].<ref name=:28/> The success of these institutes has been variable, with some failing to establish self-maintaining colonies.

==Description==

The freckled duck has a distinctive appearance. It is characterised, in adults, by dark grey to black plumage covered with small white flecks, which gives the duck the 'freckled' look. The feet, legs and bill of both sexes is of a slate grey colour. Hatchlings and juveniles are distinguished by a uniform light grey plumage, which they lose around their 32nd week when they undergo a full body moult to assume the adult plumage.<ref name=:26>{{cite journal|last1=Norman|first1=F. I.|last2=Norris|first2=K. C.|year=1982|title=Some notes on Freckled Duck shot in Victoria, Australia, 1981|journal=Wildfowl|volume=33|pages=81–87}}</ref>

The adult freckled duck is [[Sexual dimorphism|sexually dimorphic]]. On average, males are the larger sex, with average weight between 700 - 1200&nbsp;g. Females have an only slightly lower range between 600 – 1200&nbsp;g. Both sexes have a length of 50 – 60&nbsp;cm. During the breeding season particularly, the males are characterised by the base of their [[Beak|culmen]], which takes on various shades of red. Those in prime reproductive condition take on a deep red colouring, while other males may only develop lighter shades of red, or in some instances, no colouring at all. Deep red colouring of the culmen is also associated with dominance, and those with the deepest red are those likely to breed with the females of the group.<ref name=:28>{{cite journal|last1=Wilson|first1=S.|last2=Silcocks|first2=S.|year=2001|title=The husbandry and breeding of the freckled duck at Melbourne Zoo|journal=Australian Birdkeeper|volume=14|issue=9|pages=524–527}}</ref>

==Distribution and habitat==
[[File:Freckled Duck female RWD3.jpg|thumb|left|Female at Sylvan Heights Waterfowl Park in Scotland Neck, North Carolina]]
Endemic to Australia, the freckled duck is mainly situated throughout inland regions of the Eastern section of the country—including New South Wales, Victoria and Queensland. This species also has known populations in South Australia and Western Australia.<ref name=:24>{{cite journal|last1=Maher|first1=M. T.|last2=Braithwaite|first2=L. W.|year=1992|title=Patterns of waterbird use in wetlands of the Paroo, A river system of inland Australia|journal=The Rangeland Journal|volume=14|issue=2|pages=128–142|doi=10.1071/rj9920128}}</ref> Due to habitat requirements, distribution of the freckled duck directly correlates to water flow and rainfall in river catchments and wetland systems.<ref name=:10>{{cite web|publisher=Department of Environment and Heritage NSW|year=2016|title=Freckled Duck (Stictonetta naevosa)|url=http://www.environment.nsw.gov.au/savingourspeciesapp/project.aspx?ProfileID=10771}}</ref> Because of this, main populations of this species are located within the Paroo-Warrego catchment (Currawinya Lakes), Eyre-Georgine-Mulligan catchment (Lake Torquinie), and potentially at Lake Galilee. High numbers have also been recorded at the Cooper's Creek catchment, wetlands within the Barkley Tablelands, the Bulloo River catchment and Lake Gregory in central north Western Australia.<ref name=:24/>

Freckled duck habitat preference can be split into two distinct categories: breeding and non-breeding habitat. While this species does not appear to have any sort of distinct migratory pathway or seasonal migration to find suitable breeding habitat.<ref name=:1>{{cite book|last1=Blakers|first1=M.|last2=Davies|first2=S.|last3=Reilly|first3=P. N.|year=1984|title=The Atlas of Australian Birds|location=Melbourne|publisher=Melbourne University Press}}</ref> The freckled duck sometimes travels long distances to find a suitable breeding location, and seems to prefer large bodies of fresh water with thick vegetation. Usual contenders are recently flooded wetland systems and swamps.<ref name=:10/> After breeding, the freckled duck disperses to more coastal areas with more permanent bodies of water such as lakes, reservoirs, and ponds. These areas are often more exposed and contain little vegetation.<ref name=:25>{{cite book|last=Martindale|first=J.|year=1986|title=The Freckled Duck|location=Moonee Ponds, Victoria|publisher=Royal Australasian Ornithologists' Union}}</ref>

==Ecology==
===Diet===

The diet of the freckled duck has been subjected to a degree of controversy and disagreement over the years, potentially due to the versatile diet of different populations and distributions of this duck. Despite this, it is widely agreed that the freckled duck is a resilient, specialist [[filter feeder]] that consumes a range of aquatic vegetation, insects, algae, larvae and crustaceans.<ref name=:27>{{cite journal|last1=Norman|first1=F. I.|last2=Brown|first2=R. S.|year=1985|title=Gizzard grit in some Australian waterfowl|journal=Wildfowl|volume=36|pages=77–80}}</ref><ref name=:6>{{cite journal|last=Corrick|first=A. H.|year=1980|title=Freckled Ducks on lakes in the Western District, Victoria|journal=Australian Bird Watcher|volume=8|issue=1|pages=254–255}}</ref> Studies have found that the freckled duck prefers to feed in shallow water, using its bill to strain food particles from the mud or sand.<ref name=:8>{{cite journal|last=Crome|first=F. H.|year=1985|title=An Experimental Investigation of Filter-Feeding on Zooplankton by Some Specialized Waterfowl|journal=Australian Journal of Zoology|volume=33|issue=6|pages=849–862|doi=10.1071/zo9850849}}</ref>

===Social behaviour===
[[File:The birds of Australia (16769491056).jpg|thumb|right|Illustration from [[The Birds of Australia (Broinowski)|The Birds of Australia]] (1890) (with [[Pacific black duck]])]] 
A highly gregarious species, the freckled duck is known to have flock sizes ranging from 10 to 100 individuals, especially outside of breeding season. During breeding season, these flocks often break up into smaller sub-units, scattered throughout wetland and swamp systems.<ref name=:7>{{cite report|last=Craig|first=M.|year=1994|title=Captive species management plan for freckled duck: Stictonetta naevosa|location=Parkville, Victoria|publisher=Zoological Board of Victoria}}</ref>

Despite these large flock sizes, this species is lacking in demonstrative displays towards one another, with only cryptic gestures and few interactions towards fellow flock mates. The rare interaction that is observed within this species is usually of a quarrelsome nature.<ref>{{cite journal|last1=Fullagar|first1=P. J.|last2=Davey|first2=C. C.|last3=Rushton|first3=D. K.|year=1990|title=Social behaviour of the Freckled Duck Stictonetta naevosa with particular reference to the Axle-grind|journal=Wildfowl|volume=41|pages=53–61}}</ref>

===Bathing===

While there has been little research into the bathing behaviour of the freckled duck, it is known that a body of water (e.g. a swamp or dam) is essential for many natural behaviours such as feeding, mating and bathing.<ref name=:2>{{cite journal|last=Braithwaite|first=L. W.|year=1976|title=Notes on the breeding of the Freckled Duck in the Lachlan River Valley|journal=Emu|volume=76|issue=3|pages=127–132|doi=10.1071/mu9760127}}</ref> Freckled ducks have been observes preening both within water and after emerging from water while in a roosting position.<ref name=:12>{{cite journal|last=Frith|first=H. J.|year=1964|title=The downy young of the Freckled Duck, Stictonetta naevosa|journal=Emu|volume=64|issue=1|pages=42–47|doi=10.1071/mu964042}}</ref> There is no evidence that the freckled duck dust bathes or requires any other substrate for bathing.

===Reproductive behaviour===

The freckled duck is a [[Animal sexual behaviour#Polygamy|polygamous]] species that undertakes short term, seasonal [[Monogamy in animals|monogamous]] pairings in the wild. In this short term pairing, the male defends the receptive female during the pre-egg laying stage of the breeding season. During this time, the male also helps construct and defend the nest site—but leaves before the female lays her clutch, and plays no further role in rearing or defending his offspring.

The freckled duck has few pre or post [[Copulation (zoology)|copulatory]] behaviours. Copulation occurs in the water with the male approaching a receptive female, who adopts a semi-submerged orientation, with her head stretched outwards and tail raised. The male then mounts the female and clutches the feathers on the lower neck of the female during copulation. After dismounting, both sexes display bathing and preening behaviours.

The breeding season of the freckled duck is basically regular, with a generic breeding season between September and December. However, it retains the ability to breed out of season. Breeding out of season highly correlates with periods of heavy rainfall and flooding.

[[File:Freckled Duck chick SMTC.jpg|thumb|left|Chick at Sylvan Heights Waterfowl Park in Scotland Neck, North Carolina]]
Both male and female freckled ducks reach sexual maturity at around 12 months of ages when the first breeding occurrence can commence. The freckled duck has been known to continue breeding annually throughout their life, with records suggesting successful breeding in birds in excess to 10 years of age.<ref name=:28/>

The freckled duck has a standard [[Incubation period|incubation]] period of between 26 and 28 days, though some sources have recorded incubation periods of up to 35 days. The female is solely responsible for egg incubation and only leaves the eggs for short periods to feed.

The average clutch is seven eggs, but can range between four and 14 eggs.<ref name=:4>{{cite journal|last=Briggs|first=S. V.|year=1982|title=Food habits of the Freckled Duck and associated waterfowl in North-western New South Wales|journal=Wildfowl|volume=33|pages=88–93}}</ref> Clutches of up to 14 eggs can occur naturally, though this occurrence mainly appears to be the result of females 'dumping' additional eggs into another female's nest. This occurrence is common within freckled duck populations as it enables the offending females to pass on their genetic material while not expending energy to raise their hatchlings.<ref name=:19>{{cite journal|last=Jaensch|first=R.|year=2003|title=Breeding by freckled Duck Stictonetta naevosa in the Diamantina Channel Country|journal=Sunbird: The Journal of the Queensland Ornithological Society|volume=33|issue=1|pages=24–28}}</ref>

The eggs of the freckled duck are glossy, smooth and almost perfectly oval in shape. They are white in colour, ranging from shades of cream to ivory. The freckled duck egg is unique, having an exceptionally thick but soft shell unlike that of any other species. Egg measurements usually fall between 60-65mm by 45-48mm and weigh an average of 66g.<ref name=:13>{{cite journal|last=Frith|first=H. K.|year=1965|title=Ecology of the Freckled Duck Stichonetta naevosa (Gould)|journal=CSIRO Wildlife Research|volume=10|issue=1|pages=125–139|doi=10.1071/cwr9650125}}</ref>

Freckled duck hatchlings are [[precocial]], meaning they hatch fully functional and able to feed themselves. Despite this, they still need their mother for the best chance of survival. Apart from protection, the hatchlings need the mother to teach them important social cues and behaviours.<ref name=:22>{{cite book|last=Kear|first=J.|year=2005|title=Ducks, Geese and Swans|volume=2: Species Accounts (Cairina to Mergus)|location=Oxford|publisher=Oxford University Press}}</ref>

The ducklings [[fledge]] late compared with other waterfowl species, at nine weeks, when they no longer need their mother's protection. At this point, the mother and fledglings are likely to re-join a larger flock.(Flinchum, 2005)

==In captivity==

Historically, the freckled duck has been kept with limited success in captivity and ironing out the issues with captive life is still an ongoing issue. Issues with stress, breeding and mortality rates of chicks are amongst the biggest issues with keeping these ducks in captive environments. In recent years some of these concerns have been mitigated with establishments such as the Hunter Wetlands Australia and Slimbridge Wetlands UK implementing successful breeding programs, with chicks surviving to adulthood.<ref name=:28/>

The freckled duck is a highly compatible species, with various establishments holding this species in groups of various sizes, sex ratios and species with no interspecific or intraspecific aggression. However, there has been limited success with breeding programs when housed in mixed exhibits.<ref name=:3>{{cite journal|last1=Briggs|first1=S. V.|last2=Hodgson|first2=P. F.|last3=Ewin|first3=P.|year=1994|title=Changes in populations of waterbirds on a wetland following water storage|journal= Wetlands Australia|volume=13|issue=2|pages=36–48|doi=10.31646/wa.161|doi-access=free}}</ref>

Behavioural considerations are another consideration to take into account when holding a captive population of freckled ducks. The most important of these considerations is the possibility of imprinting on a subject other than the mother. [[Genomic imprinting|Imprinting]] is an instinctual phenomenon that occurs early on in life whereby the juvenile establishes a long lasting behavioural response to the parent (or another animal, person or thing that is present during the crucial imprinting period).<ref name=:17>{{cite journal|last=Hess|first=E. H.|year=1958|journal=Scientific American|title=Imprinting in animals|volume=198|issue=3|pages=81–90|doi=10.1038/scientificamerican0358-81|bibcode=1958SciAm.198c..81H}}</ref> Imprinting on human keepers is a serious consideration, as hatchlings require the mother to learn important behaviour traits—including vocalisations, feeding, and other important attributes.

==Conservation==
The species is currently classified as [[least-concern species|Least Concern]] by the [[IUCN]]. Population numbers show no definite trend, but appear to be fluctuating quite strongly, with an assessment in 2016 of 7,300 - 17,000 mature individuals. Threats include misidentification of this protected species as a game bird and consequent shooting by hunters. The ongoing destruction of swamp habitat by water diversion schemes is thought to have the capacity to result in a population decline of up to 20% within the next 15 years.<ref name="iucn status 19 November 2021" />

==References==
{{Commonscat|Stictonetta naevosa}}
{{Wikispecies|Stictonetta naevosa}}
{{Reflist|30em}}

{{Odontoanserae|B.|state=collapsed}}
{{Taxonbar|from=Q382321}}

[[Category:Anatidae|freckled duck]]
[[Category:Ducks|freckled duck]]
[[Category:Endemic birds of Australia]]
[[Category:Birds described in 1841|freckled duck]]